Rocket propellant with acrylate binder and difluoroamino plasticizer

Abstract

High energy, low radar attenuation propellant comprising (1) 25-55 weight rcent of a binder which itself comprises from 2-25 weight percent of a copolymer of acrylic acid and a lower alkyl acrylate and 75-98 weight percent of an energetic difluoroamino group containing plasticizer, (2) 0-15 weight percent aluminum or boron (3) 45-75 weight percent of an oxidizer and (4) 1/2-5 weight percent curing agent.

What is claimed as new and desired to be secured by Letters Patent of the United States is: 
     
       1. A solid rocket propellant comprising (1) about 25-55 weight percent of a binder which comprises (a) about 2-25 weight percent of a polymer which comprises about one to about 20 weight percent acrylic acid with the remainder comprising a lower alkyl acrylate and (b) about 75-98 weight percent of an energetic difluoroamino group containing plasticizer, selected from the group consisting of 1,2,3-tris[α,β-bis (difluoroamino) ethoxy] propane, hexakis (difluoroamino) propylether, 1,2-di[2,2,3-tris(difluoroamino) propoxy]-1,2-bis(difluoroamino)ethane, 1,2,4,5-tetrakis(difluoroamino)amyl methacrylate and mixtures thereof, (2) about 0-15 weight percent of a fuel selected from the group consisting of aluminum, boron and mixtures thereof, (3) about 45-75 weight percent of an oxidizer, and (4) about 1/2-5 weight percent curing agent, provided that the amount of oxidizer present be sufficient to provide for complete oxidation of said binder and said fuel. 
     
     
       2. The composition of claim 1 wherein said copolymer portion of said binder contains about 6-8 weight percent of acrylic acid with the remainder comprising a lower alkyl acrylate. 
     
     
       3. The composition of claim 2 wherein said lower alkyl acrylate is selected from the group consisting of methyl acrylate, ethyl acrylate and butyl acrylate. 
     
     
       4. The composition of claim 2 wherein said lower alkyl acrylate is ethyl acrylate. 
     
     
       5. The composition of claim 1 wherein said copolymer has an intrinsic viscosity of about 0.2-1.1 dl/g as a 0.5 gram per deciliter solution in ethyl acetate at about 25°C. 
     
     
       6. The composition of claim 1 wherein said copolymer has an intrinsic viscosity of about 0.4 - 0.8 dl/g as about a 0.5 gram per deciliter solution in ethyl acetate at about 25°C. 
     
     
       7. The composition of claim 1 wherein said fuel is aluminum. 
     
     
       8. The composition of claim 1 wherein said fuel constitutes about 1-15 weight percent of said rocket propellant. 
     
     
       9. The composition of claim 2 wherein said fuel is aluminum. 
     
     
       10. The composition of claim 1 wherein said oxidizer is selected from the group consisting of ammonium perchlorate, nitronium perchlorate, hydroxylammonium perchlorate and its derivatives, hydroxylammonium nitrate and its derivatives, potassium perchlorate, ammonium nitrate and potassium nitrate. 
     
     
       11. The composition of claim 1 wherein said oxidizer is ammonium perchlorate. 
     
     
       12. The composition of claim 1 wherein said curing agent is selected from the group consisting of difunctional epoxides, and trifunctional epoxides. 
     
     
       13. The composition of claim 1 wherein said curing agent is selected from the group consisting of ##SPC3## bisphenol A - epichlorohydrin epoxides, tolylene diisocyanate, hexamethylene diisocyanate and mixtures thereof.   
     
     
       14. A method of reducing the combustion instability of a solid rocket propellant comprising (1) about 2-25 weight percent of a binder which comprises (a) 2-25 weight percent of a polymer which comprises about one to about 20 weight percent acrylic acid and with the remainder comprising a lower alkyl acrylate and (b) about 75-98 weight percent of an energetic difluoroamino group containing plasticizer selected from the group consisting of 1,2,3-tris[α,β-bis (difluoroamino) ethoxy] propane, hexakis (difluoroamino) propylether, 1,2-di[2,2,3-tris (difluoroamino) propoxy]-1,2-bis(difluoroamino)ethane, 1,2,4,5-tetrakis (difluoroamino)amyl methacrylate and mixtures thereof, (2) about 45-75 weight percent of an oxidizer, and (3) about 1/2-5 weight percent curing agent comprising adding to said propellant 1-15 weight percent of a material selected from the group consisting of aluminum, boron and mixtures thereof provided the amount of oxidizer present is sufficient to provide for complete oxidation of said binder and said aluminum, boron and mixtures thereof.